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A classic series of experiments to determine the effects of overpopulation on communities of rats was conducted by a psychologist, John Calhoun. In each experiment, an equal number of male and female adult rats were placed in an enclosure. The rat populations were allowed to increase. Calhoun knew from experience approximately how many rats could live in the enclosures without experiencing stress due to over crowding. He allowed the population to increase to approximately twice this number. Then he stabilized the population by removing offspring that were not dependent on their mothers. At the end of the experiments, Calhoun was able to conclude that overcrowding causes a break down in the normal social relationships among rats, a kind of social disease. The rats in the experiments did not follow the same patterns of behavior as rats would in a community without overcrowding.
The females in the rat population were the most seriously affected by the high population density. For example, mothers sometimes abandoned their pups, and, without their mothers’ care, the pups died. The experiments verified that in overpopulated communities, mother rats do not-behave normally. Their behavior may be considered diseased, pathological. The dominant males in the rat population were the least affected by overpopulation. Each of these strong males claimed an area of the enclosure as his own. Therefore, these individuals did not experience the overcrowding in the same way as the other rats did. However, dominant males did behave pathologically at times. Their antisocial behavior consisted of attacks on weaker male, female, and immature rats. This deviant behaviour showed that even though the dominant males had enough living space, they too were affected by the general overcrowding.
Nondominant males in the experimental rat communities also exhibited deviant social behavior, Some withdrew completely, avoiding contact with other rats. Other nondominant males were hyperactive, chasing other rats and fighting each other.
The behaviour of the rat population has parallels in human behavior. People in densely populated areas exhibit deviant behavior similar to that of the rats in Calhoun’s experiments. In large urban areas, such as New York City, London, and Cairo, there are abandoned children. There are cruel, powerful individuals, both men and women. There are also people who withdraw and people who become hyperactive. Is the principal cause of these disorders. overpopulation Calhoun’ s experiments suggest that it might be. In any case, social scientists and city planners have been influenced by the results of this series of experiments.

A:although rats are affected by overcrowding, people are not B:data from experiments indicate that overcrowding may be an important cause of social pathology C:the social behavior of rats is seriously affected by overcrowding D:Calhoun' s experiments have influenced many people

Whenever we (hear of) a natural disaster, (even) in a distant part of the world, we feel (sympathy) for the people (to have affected).

A:hear of B:even C:sympathy D:to have affected

Birth, marriage and death: these are the greatest events in human life. Many things, good and bad, can happen to us in our lives. (79)Yet there are three days which are usually marked by some kind of special ceremony: the day we are born; the day we get married and the day we die. These are the three main events in life. We only have a choice in the second of these: we can choose whether or not to marry. But we have no choice in birth and death. All human beings— from the most primitive to the most sophisticated—are affected by these three events. The only thing that differs in each society is the way these events are celebrated. Yet all societies share common characteristics. Birth is a time of joy. The proud parents receive congratulations and presents on behalf of the new-born. Marriage is also a time of joy. The young couple go through a special wedding ceremony and receive presents to help them set up their home. (80) Death is a time of sorrow and is marked by a special ceremony and mourning. The dates of ail three events arc usually remembered.
These three events ______ all human beings.

A:affected B:have affected C:are affecting D:affect

Whenever we (hear of) a natural disaster, (even) in a distant part of the world, we feel (sympathy) for the people (having affected).

A:hear of B:even C:sympathy D:having affected

Passage 3

A:affected B:have affected C:are affecting D:affect

Male smokers are more affected by smoking than female ones because ______.

A:male smokers smoke more than female ones B:male smokers are more likely to be affected by smoking C:male smokers breath in the smoke deeper than female ones D:male smokers are more likely to be affected by other factors in envionment

Whenever we (hear of) a natural disaster, (even) in a distant part of the world, we feel (sympathy) for the people (having affected).

A:hear of B:even C:sympathy D:having affected

15 Million Americans Suffer from Social Anxiety Disorder 　　Social anxiety disorder prevents some 15 million Americans from leading normal social and romantic lives, a new survey finds. 　　The disorder leaves many isolated, ashamed and often misdiagnosed. Thirty-six percent of those with social anxiety disorder have symptoms for 10 years or more before seeking help, the Anxiety Disorders Association of America reports. 　　"Social anxiety disorder is when somebody has an intense, persistent and irrational fear of social or performance situations," Jerilyn Ross, the association’s president and CEO, said during a teleconference Wednesday. 　　"The condition causes people to avoid common, everyday situations and even other people for fear of being judged or criticized or humiliated or embarrassing themselves," Ross said. 　　Social anxiety disorder can interfere with daily routines and job performance，Ross noted. " It also makes it very difficult for people to develop friends and romantic partnerships，" she said. 　　People with this disorder recognize their fear is excessive and irrational, Rose noted. “But they feel powerless to do anything about it," she said. 　　Social anxiety disorder can start in the early teens, Dr. Mark H. Pollack, director of the Center for Anxiety and Traumatic Stress Disorders and a professor of psychiatry at Harvard Medical School, said during the teleconference. 　　"This is a disorder that starts affecting people early on1，" Pollack said. "The typical age of onset is early adolescence, age 12 or 13，and many individuals report a history of anxiety dating back to2 earlier childhood. " 　　The disorder also has physical symptoms，including heart palpitations，feelings that their throat will close up3，sweating, blushing, faintness, trembling and stammering, Ross said. 　　Among people with the disorder, 75 percent said the condition affected their ability to do normal activities. In addition, 69 percent said they didn’t want people to think they were crazy, and 58 percent said they were embarrassed by their condition，Ross said. 　　However, when the condition is diagnosed and treated, many reported improvement in their lives. In fact, 59 percent who were receiving treatment said treatment had a positive effect on their ability to have a romantic relationship. In addition, 39 percent who had received treatment said knowing that treatment can be successful aided their decision to get help, Ross noted.The last paragraph indicates that treatment of the disorder ________.

A:has no positive on those affected. B:was unavailable to those affected. C:was often rejected building those affected. D:could improve the life of those affected.